/**
*      author: Y_Yao
*      created: 2024-12-08 12:25:38
**/

#include<bits/stdc++.h>

#define int LL
using namespace std;
using LL = long long;
const LL LLINF = 1e18;
const int INF = 0x3f3f3f3f;
const int N = 1e5 + 7;
int a[N],b[N];
int dp[N];
int n;

void solve()
{
    cin >> n;
    for(int i = 1;i <= n;i++)
    {
        cin >> a[i];
    }
    for(int i = 1;i <= n;i++)
    {
        cin >> b[i];
    }

    for(int i = 1;i <= n;i++)
    {
        for(int j = 1;j <= n;j++)
        {
            if(a[i] == b[j])
            {
                dp[j] = dp[j-1] + 1;
            }
            else
            {
                dp[j] = max(dp[j-1],dp[j]);
            }
        }
    }

    cout << dp[n] << endl;
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    int t = 1;
    //cin >> t;
    while(t--)
    {
        solve();
    }
    return 0;
}